2018-10-10 22:03:03 +00:00
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---
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id: 5900f36e1000cf542c50fe81
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2020-12-16 07:37:30 +00:00
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title: 问题2:斐波那契数列中的偶数
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2018-10-10 22:03:03 +00:00
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challengeType: 5
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videoUrl: ''
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---
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2020-12-16 07:37:30 +00:00
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# --description--
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2019-05-06 21:19:25 +00:00
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在斐波那契数列中,每一项都是前两项的和(第一项和第二项除外)。如果从1和2开始,前十项是:
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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<div style='text-align: center;'>1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...</div>
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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求出斐波那契数列中值是偶数的项的和,至第`n`项(包括第`n`项)为止。
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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# --hints--
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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`fiboEvenSum(10)`应该返回188。
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2018-10-10 22:03:03 +00:00
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```js
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2020-12-16 07:37:30 +00:00
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assert.strictEqual(
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fiboEvenSum(10),
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188,
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'<code>fiboEvenSum(10)</code> should return 188.'
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);
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```
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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`fiboEvenSum(23)`应该返回60696。
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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```js
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assert.strictEqual(
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fiboEvenSum(23),
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60696,
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'<code>fiboEvenSum(23)</code> should return 60696.'
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);
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2018-10-10 22:03:03 +00:00
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```
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2020-12-16 07:37:30 +00:00
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`fiboEvenSum(43)`应该返回1485607536。
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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```js
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assert.strictEqual(
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fiboEvenSum(43),
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1485607536,
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'<code>fiboEvenSum(43)</code> should return 1485607536.'
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);
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```
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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您的函数未使用我们的测试值返回正确的结果。
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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```js
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assert.strictEqual(
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fiboEvenSum(18),
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3382,
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'Your function is not returning the correct result using our tests values.'
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);
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```
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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您的函数应返回`even`数值。
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2018-10-10 22:03:03 +00:00
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```js
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2020-12-16 07:37:30 +00:00
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assert.equal(
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fiboEvenSum(31) % 2 === 0,
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true,
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'Your function should return an <code>even</code> value.'
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);
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2018-10-10 22:03:03 +00:00
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```
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2020-08-13 15:24:35 +00:00
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2020-12-16 07:37:30 +00:00
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# --solutions--
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